1. Field of the Invention
The invention relates to a bilateral intra-aortic bypass graft for intraluminal delivery, and a method and apparatus for repairing an abdominal aortic aneurysm.
2. Description of the Prior Art
An abdominal aortic aneurysm is a sac caused by an abnormal dilation of the wall of the aorta, a major artery of the body, as it passes through the abdomen. The abdomen is that portion of the body which lies between the thorax and the pelvis. It contains a cavity, known as the abdominal cavity, separated by the diaphragm from the thoracic cavity and lined with a serous membrane, the peritoneum. The aorta is the :main trunk, or artery, from which the systemic arterial system proceeds. It arises from the left ventricle of the heart, passes upward, bends over and passes down through the thorax and through the abdomen to about the level of the fourth lumbar vertebra, where it divides into the two common iliac arteries.
The aneurysm usually arises in the infrarenal portion of the arteriosclerotically diseased aorta, for example, below the kidneys. When left untreated, the aneurysm will eventually cause rupture of the sac with ensuing fatal hemorrhaging in a very short time. High mortality associated with the rupture has led to the present state of the art and the transabdominal surgical repair of abdominal aortic aneurysms. Surgery involving the abdominal wall, however, is a major undertaking with associated high risks. There, is considerable mortality and morbidity associated with this magnitude of surgical intervention, which in essence involves replacing the diseased and aneurysmal segment of blood vessel with a prosthetic device which typically is a synthetic tube, or graft, usually fabricated of either DACRON(copyright), TEFLON(copyright), or other suitable material.
To perform the surgical procedure, requires exposure of the aorta through an abdominal incision, which can extend from the rib cage to the pubis. The aorta must be closed both above and below the aneurysm, so that the aneurysm can then be opened and the thrombus, or blood clot, and arteriosclerotic debris removed. Small arterial branches from the back wall of the aorta are tied off. The DACRON(copyright) tube, or graft, of approximately the same size of the normal aorta, is sutured in place, thereby replacing the aneurysm. Blood flow is then reestablished through the graft. It is necessary to move the intestines in order to get to the back wall of the abdomen prior to clamping off the aorta.
If the surgery is performed prior to rupturing of the abdominal aorta aneurysm, the survival rate of treated patients is markedly higher than if the surgery is performed after the aneurysm ruptures, although the mortality rate is still quite high. If the surgery is performed prior to the aneurysm rupturing, the mortality rate is typically less than 5%. Conventional surgery performed after the rupture of the aneurysm is significantly higher, one study reporting a mortality rate of 66.7%. Although abdominal aortic aneurysms can be detected from routine examinations, the patient does not experience any pain from the condition. Thus, if the patient is not receiving routine examinations, it is possible that the aneurysm will progress to the rupture stage, wherein the mortality rates are significantly higher.
Disadvantages associated with the conventional, prior art surgery, in addition to the high mortality rate, are: the extended recovery period associated with such surgery; difficulties in suturing the graft or tube, to the aorta; the loss of the existing thrombosis to support and reinforce the graft; the unsuitability of the surgery for many patients having abdominal aortic aneurysms; and the problems associated with the performing the surgery on an emergency basis after the aneurysm has ruptured. As to the extent of recovery, a patient can expect to spend form 1 to 2 weeks in the hospital after the surgery, a major portion of which is spent in the intensive care unit, and a convalescence period at home from 2 to 3 months, particularly if the patient has other illness such as heart, lung, liver, and/or kidney disease, in which case the hospital stay is also lengthened. Since the graft must be secured, or sutured, to the remaining portion of the aorta, it is many times difficult to perform the suturing step because of thrombosis present on the remaining portion of the aorta, and that remaining portion of the aorta wall may many times be friable, or easily crumbled.
Since the thrombosis is totally removed in the prior art surgery, the new graft does not have the benefit of the previously existing thrombosis therein, which could be utilized to support and reinforce the graft, were the graft to be able to be inserted within the existing thrombosis. Since many patients having abdominal aortic aneurysms have other chronic illnesses, such as heart, lung, liver and/or kidney disease, coupled with the fact that many of these patients are older, the average age being approximately 67 years old, these patients are not ideal candidates for such surgery, which is considered major surgery. Such patients have difficulties in surviving the operation. Lastly, once the aneurysm has ruptured, it is difficult to perform a conventional surgery on an expedited basis because of the extent of the surgery.
It has been previously proposed to repair abdominal aortic aneurysms by intraluminal delivery of an aortic graft disposed upon a catheter, and securing the graft within the aorta by expansion and deformation of an expandable deformable member associated with the graft by expanding and inflating a portion of the catheter which contacts the tubular member. Because of the relatively large diameter of the catheter and associated graft necessary for implantation within the aorta, some difficulties have been sometimes encountered, such as spasms associated with the access body vessel such as the femoral artery. Additional problems sometimes encountered with this method or repairing an abdominal aortic aneurysm have been kinking and/or twisting of the flexible, collapsible graft during and/or after implantation of the graft.
Accordingly, prior to the development of the present invention, there has been no bilateral intra-aortic bypass graft for intraluminal delivery, or method and apparatus for repairing an abdominal aortic aneurysm, which: does not have a relatively high morbidity and mortality rate; does not have an extended recovery period; does not require suturing the graft to the remaining aorta wall; permits the existing thrombosis therein to support and reinforce the graft; is suitable for older patients with chronic illnesses; is less susceptible to kinking and/or twisting of the graft; and is able to use a smaller diameter delivery system. Therefore, the art has sought a bilateral intra-aortic bypass graft for intraluminal delivery, and method and apparatus for repairing an abdominal aortic aneurysm which is believed to: not have a high morbidity and mortality rate; does not require an abdominal incision and general anesthesia; not require an extended recovery period; not require suturing the graft to the remaining aortic wall; permit the existing aortic wall and thrombosis therein to be retained to reinforce and support the aortic graft; be suitable for patients having other chronic illnesses; be less susceptible to kinking and/or twisting of the graft and permit the use of a smaller diameter delivery system.
In accordance with the invention, the foregoing advantages have been achieved through the method and apparatus for bilateral intra-aortic graft of the present invention. The method for repairing an abdominal aortic aneurysm in an aorta having two iliac arteries associated therewith may include the steps of: connecting a first tube to a first expandable and deformable, tubular member; connecting a second tube to a second expandable and deformable, tubular member; disposing the first tube and first tubular member upon a first catheter, disposing the second tube and second tubular member upon a second catheter, each catheter having an expandable, inflatable portion with the tubular members disposed upon the expandable, inflatable portions; intraluminally delivering the first and second tubes, tubular members, and catheters to the aorta and disposing at least a portion of each tube within the abdominal aortic aneurysm; and expanding the expandable, inflatable portion of each catheter to expand and deform the tubular members to force the tubular members radially outwardly into contact with the aorta and each other, to secure the tubular members and a least a portion of each tube within the aorta, whereby the tubes provide a bilateral fluid passageway through the abdominal aortic aneurysm.
Another feature of the present invention may include the step of simultaneously expanding the expandable, inflatable portions of each catheter. An additional feature of the present invention is that the first and second tubes may each have first and second ends, the first end of each tube being connected to a tubular member and being disposed within the aorta; and the second end of the first tube may be disposed within one of the iliac arteries, and the second end of the second end may be disposed within the other iliac artery.
A further feature of the present invention is that a third expandable and deformable, tubular member may be connected to the second end of the first tube; a fourth expandable and deformable, tubular member may be connected to the second end of the second tube; and the third and fourth tubular members are expanded and deformed to force the third and fourth tubular members radially outwardly into contact with an iliac artery by the expansion of the expandable, inflatable portion of each catheter associated with each tube. Another feature of the present invention may include the steps of forming each tube of a plurality of expandable and deformable, tubular members, each tubular member having a longitudinal axis, by aligning the plurality of tubular members with their longitudinal axes being substantially parallel with other, each tubular member being detached, and spaced apart, from adjacent tubular members; and embedding the plurality of tubular members within a layer of deformable; and expandable plastic material. The plastic material may be silicone, or polytetrafluoroethylene, expanded polytetrafluoroethylene, or expanded polyurethane.
An additional feature of the present invention may include the step of simultaneously expanding the expandable, inflatable portion of each catheter to simultaneously expand and deform the first and second tubular members and the plurality of tubular members of each tube which are embedded in the deformable and expandable plastic material. A further feature of the present invention may include the step of connecting the first and second tubular members to the first and second tubes by embedding a portion of the second ends of the first and second tubular members in the deformable and expandable plastic material of the tube to which it is to be connected.
A further feature of the present invention may include the steps of: disposing a fifth expandable and deformable tubular member upon a third catheter having an expandable, inflatable portion, with the fifth tubular member being disposed upon the expandable, inflatable portion; intraluminally delivering the fifth tubular member and third catheter to the aorta; expanding the expandable, inflatable portion of the third catheter to expand and deform the fifth tubular member to force the third tubular member radially outwardly into a connect with the aorta to secure the fifth tubular member within the aorta; the foregoing steps being conducted prior to the intraluminal delivery of the first and second tubes, tubular members, and catheters, whereupon the simultaneous expansion of the expandable, inflatable portions of the first and second catheters, the first and second tubular members are expanded and deformed radially outwardly into connect with the fifth tubular member and each other, to secure the first and second tubular members within the aorta and within the fifth tubular member.
An additional feature of the present invention may include the steps of forming each tube of a plurality of expandable and deformable, tubular members, each tubular member having a longitudinal axis, by aligning the plurality of tubular members with their longitudinal axes being substantially parallel with other, each tubular member being spaced apart from adjacent tubular members with a single, flexible connector member being disposed between adjacent tubular members; and embedding the plurality of tubular members within a layer of deformable and expandable plastic material.
In accordance with the invention, the foregoing advantages have also been achieved through the present bilateral intra-aortic bypass graft for intraluminal delivery to repair an abdominal aortic aneurysm in an aorta having two iliac arteries associated therewith. This aspect of the present invention includes: a first tube having first and second ends and a wall surface disposed between the two ends, at least a portion of the first tube adapted to be disposed within the abdominal aortic aneurysm; a second tube having first and second ends and a wall surface disposed between the two ends, at least a portion of the second tube adapted to be disposed within the abdominal aortic aneurysm; and means for securing the first ends of the first and second tubes to the aorta, the securing means including first and second tubular members, each tubular member having first and second ends, the first tube being connected to the first tubular member and the second tube being connected to the second tubular member, the tubular members having a first diameter which permits intraluminal delivery of the tubular members and tubes into the aorta and the tubular members having a second, expanded and deformed diameter, with at least a portion of the first and second tubular members in an abutting relationship, upon the application from the interior of the tubular members of a radially, outwardly extending force, the second diameter being variable and dependent upon the amount of force applied to the tubular member, whereby the tubular members may be expanded and deformed to secure the first ends of the tubular members to the aorta and a bilateral fluid passageway is formed within the abdominal aorta aneurysm.
Another feature of the present invention is that at least a portion of the first and second tubes are in an abutting relationship with each other when the first and second tubular members have their second, expanded and deformed diameter. An additional feature of the present invention is that a third expandable and deformable tubular member may be connected to the second end of the first tube; a fourth expandable and deformable tubular member may be connected to the second end of the second tube; and the third and fourth tubular members may be expanded and deformed to force the third and fourth tubular members radially outwardly into contact with an iliac artery by the expansion of the expandable, inflatable portion of each catheter associated with each tube.
A further feature of the present invention is that each tube may be formed on a plurality of expandable and deformable, tubular members, each tubular member having a longitudinal axis, the plurality of tubular members being aligned with their longitudinal axes being substantially parallel with each other, each tubular member being detached, and spaced apart, from adjacent tubular members; and the plurality of tubular members may be embedded with a layer of a deformable and expandable plastic material. The plastic material may be silicone, polytetrafluoroethylene, expanded polytetrafluoroethylene, or expanded polyurethane.
Another feature of the present invention is that the first and second tubular members may be connected to the first and second tubes by embedding a portion of the second ends of the first and second tubular members in the deformable and expandable plastic of the tube to which it is to be connected.
An additional feature of the present invention is that each tube may be formed of a plurality of expandable, and deformable tubular members, each tubular member having a longitudinal axis with a plurality of tubular members being aligned with their longitudinal axes being substantially parallel with each other; each tubular member being spaced apart from adjacent tubular members with a single, flexible connector member being disposed between adjacent tubular members; and the plurality of tubular members may be embedded within a layer of a deformable and expandable material. A further feature of the present invention is that the first and second tubular members may be connected to the first and second tubes by embedding a portion of the second ends of the first and second tubular members in the deformable and expandable plastic material of the tube to which it is to be connected.
In accordance with the present invention, the foregoing advantages have also been achieved through the present apparatus for repairing an abdominal aortic aneurysm in an aorta having two iliac arteries associated therewith. The present invention includes: first and second tubes, each tube having first and second ends and a wall surface disposed between the two ends; first and second expandable and deformable tubular members, each expandable and deformable tubular members having first and second ends and a smooth outer wall surface disposed between the first and second ends, the first end of a tube being secured to a second end of a tubular member, the expansion and deformation of the tubular members being controllable; and two catheters, each catheter having an expandable, inflatable portion associated therewith, the tubular members being releasably mounted upon the inflatable portion of each catheter, whereby upon inflation of the expandable, inflatable portion of each catheter, the tubular members are forced radially and outwardly into contact with the aorta and each other to remain secured thereto, whereby the tubes, secured to the tubular members, provide a bilateral passageway through the abdominal aortic aneurysm.
A further feature of the present invention is that each tube may be formed of a plurality of expandable and deformable, tubular members, each tubular member having a longitudinal axis, the plurality of tubular members being aligned with their longitudinal axes being substantially parallel with each other, each tubular member being detached, and spaced apart, from adjacent tubular members; and the plurality of tubular members may be embedded within a layer of a deformable and expandable plastic material. An additional feature of the present invention is that the expandable, inflatable portion of each catheter may extend along a portion of the length of each catheter a distance greater than the combined length of each tube and tubular member, whereby upon expansion and inflation of each expandable, inflatable portion of each catheter, each tubular member and its connected tube are simultaneously expanded.
The bilateral intra-aortic bypass graft for intraluminal delivery, and method and apparatus for repairing an abdominal aortic aneurysm of the present invention, when compared to previously proposed prior art grafts and methods and apparatus for repairing aneurysms, are believed to have the advantages of: a lower mortality rate; shortened recovery periods; not requiring suturing a graft to the aorta; utilizing the existing aortic wall and thrombosis therein to support and reinforce the aortic graft; being suitable for use with patients having other chronic illnesses; being less susceptible to kinking and/or twisting of the graft and permitting the use of a small diameter delivery system.